Investments - Schedule of Total Gains and Losses on Equity Securities (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Jun. 30, 2023 |
Jun. 30, 2022 |
Jun. 30, 2021 |
|
| Schedule of Investments [Abstract] | |||
| Total (losses) gains recognized on equity securities | $ (9) | $ (59) | $ 81 |
| Less: Net gains (losses) recognized on equity securities sold or impaired | 2 | 0 | (1) |
| Unrealized (losses) gains recognized on equity securities held at end of period | $ (11) | $ (59) | $ 82 |